1. Field of the Invention
The present invention relates to a high-frequency module that transmits and receives multiple communication signals with a common antenna.
2. Description of the Related Art
Various high-frequency modules have heretofore been proposed, which transmit and receive multiple communication signals using different frequency bands with common antennas. For example, a high-frequency module described in Japanese Unexamined Patent Application Publication No. 2008-10995 includes multiple duplexers each including a pair of surface acoustic wave (SAW) filters and a switch integrated circuit (IC). The SAW duplexers and the switch IC are mounted on a front surface of a multilayer body composing other circuits of the high-frequency module. External connection terminals of the high-frequency module are aligned and formed on a bottom surface of the multilayer body.
In such a high-frequency module, it is necessary to achieve high isolation between a circuit in which transmission signals are transmitted and a circuit in which reception signals are transmitted. Accordingly, the high-frequency module described in Japanese Unexamined Patent Application Publication No. 2008-10995 adopts a structure in which the external connection terminals at the reception circuit side and the external connection terminals at the transmission circuit side are aligned and formed along opposing side surfaces in a plan view of the multilayer body.
However, since the isolation is not consciously considered in the mounting pattern on the front surface of the multilayer body and the wiring pattern, for example, in the multilayer body in the structure of the high-frequency module described in Japanese Unexamined Patent Application Publication No. 2008-10995 although the isolation between the transmission side circuit and the reception side circuit is capable of being ensured for the external connection terminals of the multilayer body, the isolation may possibly be reduced. In particular, when the SAW duplexers that each multiplex and demultiplex the transmission signal and the reception signal are used, the isolation further tends to decrease.